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ppmntsc - Make RGB colors legal for NTSC or PAL color systems.
ppmntsc
[ --pal ] [ --legalonly ] [ --illegalonly ] [ --correctedonly ] [ --verbose ] [ --debug
] [ infile ]
Minimum unique abbreviations of options are acceptable.
This
program makes colors legal in the NTSC (or PAL) color systems. Often, images
generated on the computer are made for use in movies which ultimately end
up on video tape. However, the range of colors (as specified by their RGB
values) on a computer does not match the range of colors that can be represented
using the NTSC (or PAL) systems. If an image with "illegal" colors is sent
directly to an NTSC (or PAL) video system for recording, the "illegal"
colors will be clipped. This may result in an undesirable looking picture.
This utility tests each pixel in an image to see if it falls within the
legal NTSC (or PAL) range. If not, it raises or lowers the pixel's saturation
in the output so that it does fall within legal limits. Pixels that are
already OK just go unmodified into the output.
Input is from the file named
input. If input is -, input is from Standard Input. If you don't specify
input, input is from Standard Input.
Output is always to Standard Output.
This program handles multi-image PPM input, producing multi-image PPM output.
- --pal
- Use the PAL transform instead of the default NTSC.
- --verbose
- Print
a grand total of the number of illegal pixels.
- --debug
- Produce a humongous
listing of illegal colors and their legal counterparts. NOTE: This option
may produce a great deal of output.
- --legalonly
- Output only pixels that are
already legal. Output black in place of pixels that are not.
- --illegalonly
- Output only pixels that are illegal (and output them uncorrected). Output
black in place of pixels that are already legal.
- --correctedonly
- Output only
pixels that are corrected versions of illegal pixels. Output black in place
of pixels that are already legal.
ppm(5)
, ppmdepth(1)
, ppmdim(1)
,
ppmbrighten(1)
Wes Barris, Minnesota Supercomputer Center, Inc., Bryan
Henderson
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